selftests/powerpc: Remove redundant cp_abort test

Paste on POWER9 only works on accelerators and no longer on real
memory. Hence this test is broken so remove it.

Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

tools/testing/selftests/powerpc/Makefile

@@ -17,7 +17,6 @@ SUB_DIRS = alignment		\
 	   benchmarks		\
 	   cache_shape		\
 	   copyloops		\
-	   context_switch	\
 	   dscr			\
 	   mm			\
 	   pmu			\

tools/testing/selftests/powerpc/context_switch/.gitignore

@@ -1 +0,0 @@
-cp_abort

tools/testing/selftests/powerpc/context_switch/Makefile

@@ -1,5 +0,0 @@
-TEST_GEN_PROGS := cp_abort
-
-include ../../lib.mk
-
-$(TEST_GEN_PROGS): ../harness.c ../utils.c

tools/testing/selftests/powerpc/context_switch/cp_abort.c

@@ -1,110 +0,0 @@
-/*
- * Adapted from Anton Blanchard's context switch microbenchmark.
- *
- * Copyright 2009, Anton Blanchard, IBM Corporation.
- * Copyright 2016, Mikey Neuling, Chris Smart, IBM Corporation.
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License
- * as published by the Free Software Foundation; either version
- * 2 of the License, or (at your option) any later version.
- *
- * This program tests the copy paste abort functionality of a P9
- * (or later) by setting up two processes on the same CPU, one
- * which executes the copy instruction and the other which
- * executes paste.
- *
- * The paste instruction should never succeed, as the cp_abort
- * instruction is called by the kernel during a context switch.
- *
- */
-
-#define _GNU_SOURCE
-
-#include <stdio.h>
-#include <unistd.h>
-#include <stdlib.h>
-#include "utils.h"
-#include <sched.h>
-
-#define READ_FD 0
-#define WRITE_FD 1
-
-#define NUM_LOOPS 1000
-
-/* This defines the "paste" instruction from Power ISA 3.0 Book II, section 4.4. */
-#define PASTE(RA, RB, L, RC) \
-	.long (0x7c00070c | (RA) << (31-15) | (RB) << (31-20) | (L) << (31-10) | (RC) << (31-31))
-
-int paste(void *i)
-{
-	int cr;
-
-	asm volatile(str(PASTE(0, %1, 1, 1))";"
-			"mfcr %0;"
-			: "=r" (cr)
-			: "b" (i)
-			: "memory"
-		    );
-	return cr;
-}
-
-/* This defines the "copy" instruction from Power ISA 3.0 Book II, section 4.4. */
-#define COPY(RA, RB, L) \
-	.long (0x7c00060c | (RA) << (31-15) | (RB) << (31-20) | (L) << (31-10))
-
-void copy(void *i)
-{
-	asm volatile(str(COPY(0, %0, 1))";"
-			:
-			: "b" (i)
-			: "memory"
-		    );
-}
-
-int test_cp_abort(void)
-{
-	/* 128 bytes for a full cache line */
-	char buf[128] __cacheline_aligned;
-	cpu_set_t cpuset;
-	int fd1[2], fd2[2], pid;
-	char c;
-
-	/* only run this test on a P9 or later */
-	SKIP_IF(!have_hwcap2(PPC_FEATURE2_ARCH_3_00));
-
-	/*
-	 * Run both processes on the same CPU, so that copy is more likely
-	 * to leak into a paste.
-	 */
-	CPU_ZERO(&cpuset);
-	CPU_SET(pick_online_cpu(), &cpuset);
-	FAIL_IF(sched_setaffinity(0, sizeof(cpuset), &cpuset));
-
-	FAIL_IF(pipe(fd1) || pipe(fd2));
-
-	pid = fork();
-	FAIL_IF(pid < 0);
-
-	if (!pid) {
-		for (int i = 0; i < NUM_LOOPS; i++) {
-			FAIL_IF((write(fd1[WRITE_FD], &c, 1)) != 1);
-			FAIL_IF((read(fd2[READ_FD], &c, 1)) != 1);
-			/* A paste succeeds if CR0 EQ bit is set */
-			FAIL_IF(paste(buf) & 0x20000000);
-		}
-	} else {
-		for (int i = 0; i < NUM_LOOPS; i++) {
-			FAIL_IF((read(fd1[READ_FD], &c, 1)) != 1);
-			copy(buf);
-			FAIL_IF((write(fd2[WRITE_FD], &c, 1) != 1));
-		}
-	}
-	return 0;
-
-}
-
-int main(int argc, char *argv[])
-{
-	return test_harness(test_cp_abort, "cp_abort");
-}